The present invention relates to a wheel supporting frame for skates, particularly for in-line roller skates.
A problem currently felt in the manufacture of skates is that the wheels transmit directly to the frame, and the frame transmits directly to the shoe, all the stresses and/or vibrations due to uneven ground.
As a partial solution to this drawback, Italian Patent application TV91A000129 has been filed Dec. 20, 1991, disclosing a skate with in-line wheels, which comprises a wheel supporting frame between two shoulders and interacting with means for adjusting its position with respect to the support, with flexible and/or vibration-damping elements interposed.
A frame is thus described which is composed of a shoe support from which two shoulders protrude; a first seat is formed between said shoulders and accommodates a frame movable at right angles to the ground within said first seat in contrast with flexible and/or vibration-damping elements; a means for adjusting the position of the frame with respect to the support is also provided, constituted by a suitably arranged screw.
This skate has the drawback of being complicated from the constructive point of view, because the presence of several elements, which slide with respect to each other, requires the guides to be precise and non-deformable over time, this last feature being necessary owing to the various uses of the skate.
Accordingly, precise machining is required and expensive materials must be used.
The skate has also a considerable overall weight, owing to the presence of the frame which can slide with respect to the support, of the adjustment means and of the flexible and/or vibration-damping elements.
Said elements are also exclusively subjected to compressive stress and therefore they are unable for example to cushion multidirectional stresses, which can occur for example during skate thrusting or during curves or jumps or other maneuvers.
Moreover, the cross-section of the flexible and/or vibration-damping elements, adapted to cushion the stresses, is the smallest, since it corresponds to the thickness of said elements. Accordingly, it is necessary to provide thicknesses which are adequate to ensure effective cushioning and this entails considerable bulk and therefore difficulties in accommodation inside the frame.
This structural complexity can also be subject to changes and therefore to less-than-optimum operation following a plurality of impacts affecting the skate during use.
Furthermore, Italian Utility Model application TV92U000038 has been filed Jul. 9, 1992, disclosing a shock-absorber for in-line skates which comprise a frame provided with two shoulders between which said wheels are arranged, characterized in that at said pair of shoulders, along an axis which is approximately perpendicular to the ground, at least one pair of slots is provided with which at least one flexible element is associable, said flexible element having at least one engagement seat for a pivot for the rotation of said wheels.
In this shock-absorber, the flexible elements cushion only part of the stresses from the ground owing to their specific technical characteristics; substantially, it has been observed that the elastic elements are capable of cushioning only the forces that have a vertical direction with respect to the ground but are unable to cushion for example the horizontal components of frontal impacts of the wheels and do not allow, like the previous solution, to cushion multidirectional stresses.
In this case too, the need to provide the seats for the flexible elements weakens, as in the previous case, the overall structure of the frame, and the seats also require additional processing steps.
These additional steps, together with the particular dimensions, shape and quality of the flexible elements, which must ensure good operation over time and must not deteriorate due to variable weather conditions, increase the overall costs of the skate.